Catalyst prepared by steaming high silica alkali metal aluminosilicates in a matrix



United States Patent Oflice Patented July 2, I968 ABSTRACT OF THE DISCLOSURE This invention is directed towards a process for the preparation of highly active catalysts having excellent steam stability. It involves compositing an alkali metal aluminosilicate having a silicon to aluminum ratio of at least 1.5 with specific inorganic oxide matrices and then subjecting the composite to the action of steam. It has been found that by this treatment the alkali metal of the aluminosilicate in some way migrates to the inorganic oxide matrix and is trapped therein thereby forming a highly stable and active catalyst composition.

CROSS-REFERENCES T RELATED APPLICATIONS This application is a continuation-in-part of application Ser. No. 492,309, filed Oct. 1, 1965, now abandoned; the

same being a continuation-in-part of application Ser. No. 379,813, filed July 2, 1964 (now Patent No. 3,257,310),

application Ser. No. 449,603, filed Apr. 20, 1965 (now Patent No. 3,210,267), and application Ser. No. 466,096, filed June 22, 1965 (now Patent No. 3,271,418). Application Ser. No. 621,138, filed concurrently herewith, claims catalysts herein disclosed and prepared by steaming of alkali metal zeolites mixed with matrix material and a polyvalent metal compound.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a new and improved cracking catalyst characterized by unusual ability to selectively crack high molecular weight hydrocarbon oils to lighter material boiling in the gasoline range. In one embodiment, the invention is concerned with a catalyst composition comprising the reaction product of a crystalline alkali metal aluminosilicate with an inorganic oxide matrix wherein interaction of the aluminosilicate and matrix components is controlled to produce a highly active and selective catalyst. In another embodiment, the invention is directed to a method for producing such catalyst.

DESCRIPTION OF THE PRIOR ART Catalyst of enhanced activity and having a markedly superior selectivity for production of gasoline by cracking of high boiling hydrocarbons has been widely adopted following the discoveries described in US. Patents such as 3,140,249 (Plank et al., July 7, 1964) and 3,257,310 (Plank et al., June 21, 1966). As shown in the earlier of these patents, crystalline aluminosilicates in such porous matrices as silica-alumina gels and equivalent refractory porous solids known to the catalytic cracking art are unusually efiective cracking catalysts when so treated as to have low content of alkali metal. Effective treatments there shown include base exchange with aqueous solutions which contain cations capable of replacing the original alkali metal content of the aluminosilicates. The later patent reveals benefits obtained by steam treatment of such composites.

SUMMARY OF THE INVENTION This invention provides a technique for the preparation of highly active catalysts of excellent stability to steam, hence high stability under reaction conditions in which the catalyst is exposed to high temperature steam atmospheres, as in many types of commercial catalytic cracking plants. The new method operates on aluminosilicates which are inherently unstable to steam due to concentration of alkali metal cations. Such high alkali metal aluminosilicates of silicon to aluminum ratio equal to at least about 1.5 are combined with inorganic oxide matrix material, preferably of high alumina content, to form a reaction mixture, which is subjected to the action of steam. In these reaction mixtures, the agent which is normally destructive of these alkali metal aluminosilicates converts the same to a highly active, steam-stable catalyst.

DESCRIPTION OF SPECIFIC EMBODIMENTS In accordance with the present invention, it has been discovered that highly active and stable cracking catalysts can be prepared from crystalline alkali metal aluminosilicates by thermally interacting the aluminosilicate with an inorganic oxide matrix so as to achieve fixation of alkali metal cations within the matrix component. It has been discovered that stability can be obtained without necessitating pre-exchange of an alkali metal aluminosilicate by providing a sink for irreversible removal of alkali metal into a second component of the catalyst composite itself. Thus, when an alkali metal crystalline aluminosilicate is mixed with an inorganic oxide matrix and thermally interacted in the presence of steam as hereinafter defined, the alkali metal migrates irreversibly into the inorganic oxide matrix and becomes insoluble. While the total alkali metal content of the composite remains the same and may be high, i.e., greater than 1 weight percent, the amount of exchangeable alkali metal in the composite is below about 0.6 weight percent and excellent stability is achieved. In contradistinction to previous methods for preparing highly active crystalline aluminosilicate catalysts wherein the alkali content of the aluminosilicate has been minimized and reduced by substantial replacement to obtain steam-stable compositions, the present invention provides a means whereby the assynthesized or unstable alkali metal form of the crystalline aluminosilicate can be used directly to obtain stable catalyst compositions of unusually high catalytic activity and selectivity. The enhanced activity of the catalyst is dependent upon controlled interaction of the crystalline alkali metal aluminosilicate zeolite with the inorganic oxide matrix so as to achieve fixation and irreversible migration of alkali metal cations within the matrix component. The unusual use of the matrix material in accordance with the invention serves to provide a dual effect of rendering alkali metal cations inactive and contributing unique properties to the resulting combination which are not possessed by either component alone.

The present invention is concerned in one aspect with a method for the preparation of a catalyst composition comprising an alkali metal crystalline aluminosilicate zeolite and an inorganic oxide matrix wherein the catalyst is prepared by forming a mixture of both components, thermally reacting the mixture at temperatures of at least 800 F. in the presence of steam for a period of at least one-half hour, and thereafter recovering the resulting product being characterized by having less than 0.6 weight percent, based on the total composite, of exchangeable alkali metal when treated with excess 25 percent aqueous ammonium chloride solution at 180 F. for 24 hours.

The aluminosilicates used for purposes of the invention are base-exchangeable alkali metal or alkali metal-com taining crystalline aluminosilicates which are unstable to steam. As defined herein, unstable to steam means that such aluminosilicate will lose greater than 50 percent and usually more than 70 percent of its rigid three-dimensional structure as defined by X-ray crystallinity, sorption capacity and/or surface area, when treated with 100 percent steam at 1200 F. for 24 hours under a pressure of 15 p.s.i.g. Aluminosilicates meeting this definition include the as-synthesized or alkali metal forms as well as alkali metal-containing aluminosilicates which have been partially pre-exchanged with one or more cations to reduce the original alkali metal content. As an example, alkali metal aluminosilicates having the crystallographic structure of faujasite, such as zeolites X and Y, contain approximately 14 weight percent and weight percent sodium, respectively, and will lose at least 99 percent of their surface area when treated with steam under the conditions above defined. Similarly, when the alkali metal form of zeolite Y is base-exchanged with rare earth cations and partially reduced to a sodium level of 4.3 Weight percent, 75 percent of its surface area is lost upon steaming. At a sodium level of 6 weight percent, a 97 percent loss of surface area is obtained. Similarly, when the sodium level of zeolite X is reduced to 5.9 weight percent with rare earth cations, a 98 percent loss of surface area is obtained upon steaming. As a general guide, it may be stated that base-exchangeable crystalline alumino'silicates which contain at least 4 weight percent alkali metal are unstable to steam within the definition above described. As a result of being unstable to steam, such aluminosilicates are extremely poor catalysts for the conversion of hydrocarbons.

The crystalline aluminosilicates utilized in accordance with the invention may be expressed in terms of oxide mole ratios which correspond to the general formula:

(@M O I (l-JUMZO:AlzOywSiOrnyHzO wherein M represents an alkali metal cation; M represents a polyvalent metal having a valence of n; x is a number such that the alkali metal content is at least 4 weight percent; w is a number between 3 and 20 representing the moles of SiO;,, and y the moles of H 0. Many of these aluminosilicates are found in nature, for example, chabazite and erionite; while others, such as zeolites A, X, L and Y, may be synthesized by reacting silica and alumina with caustic at temperatures of about 100 C. for periods of minutes to 90 hours or more. The aluminosilicates are essentially the dehydrated forms of crystalline hydrous siliceous zeolites containing varying quantities of alkali metal and aluminum with or without other metals. The alkali metal atoms, silicon, aluminum and oxygen in these zeolites are arranged in the form of an aluminosilicate salt in a definite and consistent crystalline pattern and may be base-exchanged with numerous cations. The structure contains a large number of small cavities, interconnected by a number of still smaller holes or channels. The alkali metal-containing aluminosilicates used in preparation of the present catalyst have a uniform pore structure comprising openings characterized by pores having openings of uniform size greater than 4 and less than 15 Angstrom units, the pore openings being suificiently large in three dimensions to admit the molecules of the hydrocarbon charge desired to be converted. The preferred crystalline aluminosilicates will have a rigid three-dimensional network characterized by a system of cavities and interconnecting ports or pore openings, the cavities being connected with each other in three dimensions by pore openings or ports which have minimum diameters of at least 6 Angstrom units.

Aluminosilicates falling within the scope of the above formula are well known and include synthetic materials designated as zeolites Y, L and T and natural aluminosilicates such as gmelinite, erionite, faujasite and chabazite. The useful aluminosilicates have a sorption capacity of 760 millimeters and C. of at least 4 weight percent of normal butane. Particularly preferred materials are the crystalline alkali metal aluminosilieatcs which have a silica to alumina mole ratio of at least 3 and a pore size of between 6 and 15 Angstrom units.

Pursuant to the teachings of the invention, the alkali metal aluminosilicate is combined, dispersed or otherwise intimately admixed with an organic oxide matrix which, under the thermal conditions hereinbelow described, is capable of interacting with the aluminosilicate so as to achieve fixation and irreversible migration of alkali metal cations within the matrix component. The inorganic oxide matrix which can be employed for this purpose is capable of wide selection and may be amorphous, crystalline or a material which is both crystalline and amorphous.

Typical matrix components are the alumina-containing siliceous inorganic oxides which occur naturally, such as the various clay minerals. Representative clays include attapulgite, kaolin, sepiolite, polygarskite, kaolinite, bentonite, montmorillonite, illite, chlorite and halloysite. Of the foregoing, the preferred material-s are the two-layered clays such as the members of the kaolinite group, i.e., kaolinite, dickite, nacrite, and halloysite. The clay materials may be utilized directly in their natural or raw state, or may be previously water-washed, acid-treated, caustictreated, calcined or otherwise treated prior to mixing with the aluminosilicate.

Other preferred matrix materials are the alumina-containing inorganic oxides which are prepared by synthetic formulation of composites of alumina with a hydrous inorganic oxide of at least one metal selected from the group consisting of metals of Groups II-A, IIIB and lV-A of the Periodic Table. Such components include, for example, silica-alumina, alumina-zirconia, alumina-titania, alumina-beryllia, as well as ternary combinations such as silica-alumina-thoria, silica-alumina-zirconia, and silicaalumina-magnesia. Particular preference is accorded synthetic composites of silica-alumina, alumina-zirconia and silica-alumina-zirconia. In the foregoing composites alumina is generally present as the minor component and the other oxides of metals are present in major proportion. Thus, the alumina content of such composites is generally Within the approximate range of at least 10 weight percent, preferably 15 to 55 weight percent, with the other hydrous inorganic oxide content ranging from to 90 weight percent. When the inorganic oxide matrix is an amorphous material such as a composite of alumina with a hydrous inorganic oxide of a metal, such as above described, a high alumina content, e.g., 15 to weight percent, preferably 25 to 55 weight percent, is desired in order to facilitate fixation of the alkali metal cations within the matrix component. Additionally, such composites are preferably prepared in the form of a finely divided homogeneous precipitate or co-gel by techniques which are Well known in the art.

The alkali metal aluminosilicate is dispersed, combined or otherwise admixed intimately with the matrix component in any desired manner such as in a ball mill, pulverizer, jet mill, muller mixer or the like. The mixing operation can be effected with dry materials, or in the presence of an aqueous or non-aqueous medium, e.g., water or an inert solvent such as benzene. The alkali metal aluminosilicate usually has a particle size of less than 40 microns, preferably less than 10 microns, and is mixed with the inorganic oxide matrix in the form of a slurry. The mixture can be then extruded, pelleted or otherwise agglomerated to obtain uniform or irregularly shaped particles which may vary in size from 20 microns to A1 inch in diameter. Following the formation of pellets the composite is dried, if necessary, to remove substantially all the liquid therefrom. While drying may be effected at ambient temperatures, it is more satisfactory to facilitate the removal of liquid by maintaining the composition at a temperature between about 150 F. and 1000 F. for 4 to 48 hours.

As hereinafter shown, it is a critical feature of the invention that the inorganic oxide matrix component be present in the final composite in an amount sufficient to achieve fixation and irreversible migration of alkali metal cations within the matrix component when the aluminosilicate and matrix component are subsequently thermally interacted. When the as-synthesized or alkali metal form of the aluminosilicate is employed, the matrix component must be used in an amount corresponding to at least 50 percent by weight, and preferably 70 percent by weight or more, based on the final composite. When aluminosilicates are used which have been partially pre-exchanged with one or more polyvalent cations to reduce the original alkali metal content, the matrix component may be used in an amount as small as 40 percent by weight, based on the final composite. In this embodiment, less matrix is required since the partially exchanged aluminosilicate even though unstable to steam, i.e., containing at least 4 percent by weight alkali, contains a lesser amount of alkali metal cations for fixation within the matrix component. The amount of aluminosilicate employed will be less than 60 Weight percent and preferably less than 25 weight percent, based on the final composite.

After formation of the composite, the alkali metal aluminosilicate and matrix component are thermally interacted with one another at elevated temperatures of at least 800 F., preferably 1100 F. or higher, in the presence of steam for a period of at least one-half hour. As will appear from data set forth hereinafter, the exposure of the catalyst composite to thermal conditions in the presence of steam serves to render alkali metal cations harmless by effecting fixation and irreversible migration of the alkali metal cations within the framework of the matrix component. The thermal interaction may be accomplished at temperatures ranging from 800 F. up to the decomposition temperature of the particular alumino' silicate employed, which is generally less than about 1600 F., in an atmosphere consisting of a substantial amount of steam ranging from 5 to 100 percent by volume. The steam treatment may be effected at subatmospheric, atmospheric or superatmospheric pressures. Thermal interaction is controlled to achieve fixation of the alkali metal cations so that the final composite contains less than 0.6 weight percent, preferably less than 0.4 weight percent, based on the final composite, of exchangeable alkali metal. At a temperature of 1200 F. under a steam pressure of 1 atmosphere for a period of 1 hour the composite will contain less than 0.6 weight percent exchangeable alkali metal as determined by base exchange with an excess of 25 percent aqueous ammonium chloride solution at 180 F. for 24 hours. By increasing the period of time, however, e.g., from 2 to 25 hours or more, the composite will contain less than about 0.4 Weight percent and may contain less than 0.2 weight percent exchangeable alkali metal. The preferred temperature range thus ranges from at least 1100 F. for a period of at least one-half hour in the presence of steam under atmospheric pressure.

In general, control of the fixation operation can be readily achieved by conducting steaming of the reaction mixture as a step in the catalyst manufacturing process before applying the product to use as a catalyst. In the alternative, this final step can be conducted in the equipment in which the catalyst is to be employed. For example, it is common practice to operate many types of catalytic cracking units under conditions which provide steam atmospheres of adequate concentration at various points. The charge stock may be admitted to the reactor admixed with steam. Steam may be employed as purging or sealing medium, or both, between reactor and regenerator. Indeed, the regenerator may, itself, provide adequate concentration of steam as a sum of moisture in the air plus that generated by line burner, if any, and that resulting from hydrogen content, if any, of the coke burned from the catalyst in regeneration. The requisite time of steaming need not be one uninterrupted period, but may be the accumulation of successive shorter intervals. The essential feature is that the agent normally destructive of the catalytic agent may, in a proper reaction mixture, be the essential stabilizing agent. Thus, an effective mode of applying the invention is to supply the raw reaction mixture as make-up to an operating catalytic cracker.

The method heretofore described is applicable, with or Without modification, to treatment of aluminosilicates of high silica content, a ratio of silicon to aluminum of at least about 1.5.

In a modification usable regardless of silicon to aluminum ratio of the aluminosilicate, various metal compound promoters can be incorporated within the aluminosilicatematrix reaction mixture for the purpose of enhancing catalytic behavior of the final catalyst product. Preferred promoters are salts and oxides of polyvalent metals such as aluminum, manganese, magnesium, calcium, rare earth, iorn, chromium and the like. The preferred compounds are the salts of the rare earths, particularly the rare earth chlorides. The amount of promoter may range from 0 to 25 Weight percent based on the final catalyst composite and is preferably within the range of 0.5 to 15 weight percent.

Cracking, utilizing the catalyst described herein, may be carried out at catalytic cracking conditions employing a temperature within the approximate range of 700 F. to 1200 F. and under a pressure ranging from subatmospheric pressure up to several hundred atmospheres. The contact time of the oil with the catalyst is adjusted in any case according to the conditions, the particular oil feed and the particular results desired to give a substantial amount of cracking to lower boiling products. Cracking may be effected in the presence of the instant catalyst utilizing well-known techniques including, for example, those wherein the catalyst is employed as a fluidized mass, fixed bed, or as a compact particle-form moving bed.

The catalysts of the present invention are especially suitable for use in both the moving-bed and fluid cracking processes. In the moving-bed process (e.g., Thermo for Catalytic Cracking or TCC), catalyst particles are used which are generally in the range of about 0.08 to 0.25 inch in diameter. Useful reaction conditions include temperature above about 850 F., pressures from subatmospheric to approximately 3 atmospheres, catalyst to oil ratios of about l.5l5 and liquid hourly space velocities of about 0.5 to 6. In the fluidized catalytic cracking process (or FCC) catalyst particles are used which are generally in the range of 1.0 to 150 microns in diameter. The commercial FCC processes include one or both of two types of cracking zones-a dilute bed (or riser) and a fluid (or dense) bed. Useful reaction conditions in fluid catalytic cracking include temperatures above 850 F., pressures from subatmospheric to 3 atmospheres, catalyst-to-oil ratios of 1 to 30, oil contact time less than about 12 to 15 seconds in the riser, preferably less than about 6 seconds, wherein up to percent of the desired conversion may take place in the riser, and a catalyst residence (or contact) time of less than 15 minutes, preferably less than 10 minutes, in the fluidized (or dense) bed.

The catalysts described herein may also be used to catalyze a wide variety of different organic conversion processes other than cracking. A typical example is the use of such catalysts for hydrocracking hydrocarbon fractions such as gas oils, residual oils, cycle stocks, whole topped crudes and heavy hydrocarbon fractions derived by the destructive hydrogenation of coal, tars, pitches, asphalts, and the like. The hydrogenation component can include metals, oxides and sulfides of metals of the Periodic Table which fall in Group V including vanadium, Group VI including chromium, molybdenum, tungsten and the like, and Group VIII including cobalt, nickel, platinum, palladium, rhodium and the like, and combinations of metals, sulfides and oxides of metals of the foregoing such as nickel-tungsten sulfide, cobalt-molybdenum oxide, cobalt-molybdenum sulfide and the like. The amount of hydrogenation component can range from about 0.1 to about 30 weight percent based on the catalyst. The hydrogenation component may be combined with the catalyst composite in any feasible manner, such as impregnation, coprecipitation, cogellation, mechanical admixture and the like. The hydrocracking operation is generally carried out at a temperature between about 400 F. and about 950 F. The hydrogen pressure in such operation is generally within the range of about 100 and about 3000 p.s.i.g. and, preferably, about 350 to about 2000 p.s.i.g. The liquid hourly space velocity, i.e., the liquid volume of hydrocarbon per hour per volume of catalyst is between about 0.1 and about 10. In general, the molar ratio of hydrogen to hydrocarbon charge employed is between about 2 and about 80, and preferably between about and about 50.

The following examples illustrate the best mode now contemplated for carrying out the invention. In each of the following catalyst preparations, the compositions were dried at 1000 F. for hours prior to thermal interaction. In each example where exchangeable sodium is shown, this was determined on a small test sample. A 5 gram sample of the catalyst was contacted for 24 hours at 180 F. with 20 grams of a 25% solution of NH cl. After washing free of chloride ions, the sample was dried and calcined and the sodium content determined. Calculations were made by subtracting the sodium content of the exchanged sample from that of the original sample. Catalytic data were obtained on the remainder of the example.

The following examples illustrate the use of various inorganic oxide matrices which can be used in accordance with the invention.

Example 1 aqueous ammonium chloride solution at 180 F. for 24 hours, the sample analyzed 1.66 weight percent sodium.

Example 2 In the preparation of this example, a ZrO /Al O matrix was first prepared by mixing 228 grams and 655 grams Al (SO -18H O and 1800 cc. H 0 and then precipitating the solution with NH OH to 6.2 pH using 529 cc. NH OH (29.9 weight percent NH This precipitate was washed free of sulfate ion, then air dried at room temperature. To 437.8 grams of this hydrous material (63.3 grams solids) was added 54.7 grams of sodium faujasite (Si/Al 1.5; 50.5% solids) and 590 cc. water in a blender. The resulting slurry, after being dried to remove the liquid phase, was thermally treated at 1225 1". with 100% steam for 20 hours at atmospheric pressure. The composite analyzed approximately 1.0 weight percent sodium. After treating a test sample of the composite with an excess of 25 aqueous ammonium chloride solution at 180 F. for 24 hours, the sample analyzed 0.48 weight percent sodium.

The cracking activity of the catalyst composites prepared in Examples 1 and 2 is illustrated in Table 1 below by their ability to catalyze the conversion of a Mid- Continent gas oil having a boiling range of 450 F. 950 F. to gasoline having an end point of 410 F. Vapors of the gas oil are passed through the catalyst at a temperature of about 900 F., substantially at atmospheric pressure, at a feed rate of 2.0 to 4.0 volumes of liquid oil per volume of catalyst per hour for ten minutes. The method of measuring the catalyst was to compare the various product yields obtained with such catalyst with yields of the same products given by conventional silica-alumina catalyst at the same conversion level. The differences (delta values) shown hereinafter represent the yields given by the present catalyst minus yields given by a conventional silica-alumina catalyst.

The catalytic results summarized in Table 1 clearly demonstrate that the composition prepared in accordance with the invention are highly active and selective in pro ducing more C +gasoline than the standard silica-alumina reference catalyst.

TABLE 1 Example 1 Composition:

N 2., wt. percent 1. 70 Na, wt. percent after exchange Na, wt. percent exchangeable Catalytic Evaluation:

Conditions:

LHSV

C/O Conversion, v01. percent 0 Gasoline, vol. percent Total Cls, vol. pcrcent Dry Gas, wt. percent Coke, wt. percent 11;, wt. percent Delta Advantage over Si/Al: C +Gasoline,

vol. percent Examples 3, 4 and 5 below illustrate the use of various types of crystalline aluminosilicates which can be employed in accordance with the invention.

Example 3 In the preparation of this example, 29.5 grams (84.9% solids) of a crystalline aluminosilicate identified as zeolite Example 4 In the preparation of this example, 25.9 grams of a crysstalline aluminosilicate identified as zeolite X (Si/Al l.5; 96.8% solids) were blended with 277 grams raw halloysite clay (81.3% solids) and 600 cc. water in a blender for 2 minutes. The resulting slurry, after being dried to remove the liquid phase, was thermally treated at 1225 F. with steam for 20 hours at atmospheric pressure. The composite analyzed approximately 1.44 weight percent sodium. After treating a test sample of the composite with an excess of 25% aqueous ammonium chloride solution of F. for 24 hours, the sample analyzed 1.42 weight percent sodium.

Example 5 In the preparation of this example, 30.7 grams of a crystalline aluminosilicate (81.2% solids) identified as zeolite ZSM-3 (0.3-0.8 Li O:0.70.2 Na O:Al O :2.84 SiO :09 H O) were blended with 257 grams McNamee kaolin clay (87.4% solids) and 600 cc. water in a blender for 2 minutes. The resulting slurry, after being dried to remove the liquid phase, was thermally treated at 1225 F.

TABLE 2 Example 3 4 Composition:

Na, wt. percent Na, wt. percent after exchange Na, wt. percent exchangeable Catalytic Evaluation:

Conditions:

LHSV

C/O Conversion, vol. percent. C +Gaso1ine, vol. percent Total Cis, vol. percent. Dry Gas, wt. percent... Coke, wt. percent. H wt. percent Delta Advantage Over Si/Al: 05-1-6350 line, vol. percent Examples 6, 7 and 8 illustrate the use of steam-unstable alkali metal aluminosilicates in which the original sodium cations have been partially exchanged with other metal cations.

Example 6 In this example, 59.8 grams of a partially exchanged rare earth zeolite X aluminosilicate (6.3 weight percent Na) were mixed with 229 grams McNamee kaolin clay and 600 cc. water for 2 minutes in a blender. The resulting slurry, after being dried to remove the liquid phase was thermally treated at 1225 F. with 100% steam for hours at atmospheric pressure followed by a second thermal treatment at 1200 F. with 100% steam for 24 hours under a pressure of 15 p.s.i.g. The product analyzed 0.84 weight percent sodium. Upon treating a test sample of the composite with an excess of 25% aqueous ammonium chloride solution at 180 F. for 24 hours substantially no sodium was removed from the sample.

Example 7 In this example, a partially exchanged calcium zeolite X aluminosilicate (6.3 Weight percent Na) was mixed with McNamee kaolin clay in the same manner as Example 6. The sample analyzed 1.3 weight percent sodium and upon treating a test sample of the composite with excess ammonium chloride solution substantially no sodium was removed from the sample.

TABLE 3 Example 6 7 8 Composition:

Na, wt. percent Na, wt. percent exchangeable Catalytic Evaluation:

Conditions:

0. 84 Nil Coke, wt. percent- H2, wt. percent Delta Advantage Over Si/Al: C +Gasoline, vol. percent Examples 9 through 15 illustrate various types of metal salt promoters which can be employed in the preparation of the catalyst compositions of the invention.

Example 9 In the preparation of this example, 25.9 grams of a crystalline aluminosilicate indentified as zeolite X (96.8 wt. percent solids) was mixed with 18.65 grams of rare earth chloride hexahydrate, 257 grams of McNamee kaolin clay (87.4% solids) together in 600 cc. water for two minutes in a blender. The resulting slurry, after being dried to remove the liquid phase, was thermally treated at 1200 F. with 100% steam for 24 hours under a pressure of 15 p.s.i.g. The product analyzed. 1.3 wt. percent sodium. After treating a test sample of the composite with an excess of 25% aqueous ammonium chloride solution at 180 F. for 24 hours, the sample analyzed 1.23 wt. percent sodium.

Example 10 In the preparation of this example, 30.1 grams of sodium faujasite (Si/Al 1.5; 83% solids) was mixed with 11.1 grams of rare earth chloride hexahydrate, 258 grams of McNamee kaolin clay together in 600 cc. water for two minutes in a blender. The resulting slurry, after being dried to remove the liquid phase, was thermally treated at 1200 F. with 100% steam for 24 hours under a pressure of 15 p.s.i.g. The product analyzed 0.75 wt. percent sodium. Upon treating a test sample of the composite with an excess of 25% aqueous ammonium chloride solution at 180 F. for 24 hours, substantially no sodium was removed.

Example 11 This example was prepared in a manner identical to Example 10, using the same procedure and amounts of sodium faujasite, clay and rare earth salt. Instead of mixing in water, benzene was used. The product analyzed 1.0% sodium. After treating a test sample of the composite with an excess of 25% aqueous ammonium chloride solution at 180 F. for 24 hours, the sample analyzed 0.98 wt. percent sodium.

Example 12 In the preparation of this example, 29.5 grams of a crystalline aluminosilicate identified as sodium faujuasite (Si/Al 1.5; solids) was mixed with 11.5 grams Cr(NO -9H O, 257 grams McNamee kaolin clay in 800 cc. of benzene for two minutes in a blender. The resulting slurry, after being dried to remove the liquid phase, was thermally treated at 1225 F. with steam for 20 hours under atmospheric pressure. The product analyzed 1.04 wt. percent sodium. After treating a test sample of the composite with an excess of 25 aqueous ammonium chloride solution at 180 F. for 24 hours, the sample analyzed 0.77 Wt. percent sodium.

Example 13 This example was prepared in a manner identical to Example 12 except that the metal salt employed was 6.95 grams of ZrOCl '8H O. The product analyzed 0.94 wt. percent sodium. After treating a test sample of the composite with an excess of 25% aqueous ammonium chloride solution at 180 F. for 24 hours, the sample analyzed 0.79 wt. percent sodium.

Example 14 This example was prepared in a manner identical to Example 12 except that the metal salt employed was 8.75 grams of MgCl 6H O. The product analyzed 1.02 wt. percent sodium. After treating a test sample of the composite with an excess of 25% aqueous ammonium chloride solution at 180 F. for 24 hours, the sample analyzed 0.97 Wt. percent sodium.

1 1 Example 15 The catalytic evaluation of the data shown in Table 4 again illustrates the exceptional activity and selectivity of the catalyst compositions prepared in accordance with the invention.

final silicate solution had a specific gravity of 1.324 at 78 F.

Acid solution: Lbs. Water 20.6 Al (SO -'18H O 3.03 H 50 97.6 wt. percent 1.38

Sp. Gr. 1.102 at 86 F.

The silicate and acid solutions were mixed together continuously adding 302 cc. per min. silicate solution at 140 F. with 190 cc. per min. acid solution at room temperature. The resulting sol having a 10.1 pH and a TABLE Example 9 10 11 12 13 l4 l5 Composition:

Na, wt. percent l. 3 0.75 1. 1. 04 0. 94 1.02 0. 95 Na, wt. percent after exchange 1. 23 0. 98 0.77 0. 79 0. 97 0.89 Na, wt. percent exchangeable .07 Nil 02 27 .15 06 Catalytic Evaluation:

Conditions:

LHSV- 4 4 4 4 4 4 4 C/O 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Conversion, vol. percent. 05. 0 72. 5 62. 1 67.8 71. 8 74. 3 72. 4 C +Gasoline, vol. percent. 55. 2 62. 4 54. 7 57. 8 58. 4 62.7 61.0 Total Cls, vol. percent 12.4 14.6 12.2 14.1 16. 3 15. 1 15.3 Dry Gas, wt. percent 5.8 5.8 5.2 6. 1 7. 6 6.8 6. 7 Coke, wt. percent 2.4 2.0 0.9 1. 5 1.9 2.1 1.8 Hz, wt. percent. 0.08 0.05 0. 04 0.05 0.01 0.05 0.0 Delta Advantage Over S C.

Gasoline, vol. percent +10. 2 +14. 0 +11- 2 +11. 4 +10. 3 +13. 0 +12. 7

The following Examples 16 to 18 illustrate that the catalyst compositions of the invention can be prepared in preformed shapes for use in commercial units.

Example 16 In this example, 289 grams of sodium faujasite (Si/Al l.5; 51.8 solids), 862 grams of McNamee kaolin clay (87% solids) and 105.6 grams bentonite clay (94.6% solids) were mixed together in a blender adding 4000 cc. water. Nine pounds of this slurry was filtered and then extruded hydraulically under 5 to 7 tons pressure through a die having holes. A portion of the wet extrudate was cut to about one-quarter inch in length and thermally treated at 1300 F. with 100% steam for 24 hours at atmospheric pressure. The original sodium content of the composite was 1.7 wt. percent. After the thermal treatment, a test sample was treated with an excess of 25% aqueous ammonium chloride solution at 180 F. for 24 hours and the sample analyzed 1.36 wt. percent sodium.

Example 17 This example was prepared in a similar manner to the above example. Half of the initial slurry prepared in Ex- This catalyst was made in head form by mixing the following solutions.

Silicate solution (A): Lbs.

Q brand silicate (SiO -28.9 wt. percent; Na o- 8.9 wt. percent; H O62.2 wt. percent) 8.72 Water 4.36 McNamee kaolin clay 11.22 Silicate solution (B):

Sodium faujasite (Si/Al l.5; 51.8 wt. percent solids) 2.66 Water 1.62

These two solutions were mixed together along with Maresperse Compound to aid in dispersing the slurry. The

gel time less than one second was formed into particles by spraying the sol into air. The formed particles were subsequently processed by Water washing free of soluble ions and then dried at 450 F.

The resulting composition, which analyzed 1.3 wt. percent sodium, was thermally treated at 1200 F. with steam for 24 hours under a pressure of 15 p.s.i.g. After treating a test sample of the composite with an excess of 25% aqueous ammonium chloride solution at 180 F. for 24 hours, the sample analyzed 1.29 wt. percent sodium.

Table 5 below shows that the compositions prepared in Examples 16-18 are excellent catalysts for cracking gas oil.

TABLE 5 Example Composition:

Na, wt. percent Na, wt. percent after exchange... Na, wt. percent exchangeable Catalytic Evaluation:

Conditions:

LHSV C/O Conversion, vol. percent C l-Gasoline, vol. percent Total C s, vol. percent Dry Gas, wt. percent Coke, wt. percent H2, wt. percent Delta Advantage Over /A C +Gas0- line, vol. percent +10 Examples 19-21 illustrate the use of varying amounts of the inorganic oxide matrix components and the effect thereof on catalytic behavior.

Example 19 Example 20 In the preparation of thi example, 77.5 grams of sodium faujasite (Si/Al 1.5; 80.6% solids) was mixed with 71.9 grams McNamee kaolin clay (87% solids) and 300 cc. water for 2 minutes in a blender. The resulting slurry, after being dried to remove the liquid phase, was thermally 13 treated at 1200 F. with 100% steam for 24 hours under a pressure of 15 p.s.i.g. The product analyzed 4.4 wt. percent sodium.

Example 21 lid The following example illustrates the preparation of a catalyst which is useful for hydrocracking hydrocarbon fractions such as petroleum gas oils as previously described.

In the preparation of this example, 191.5 grams of so- Example (1111111 falliasite 734% Solids) Was mixed In this preparation, a composite containing 30 weight With 1145 grams McNamee kaolin y (874% Solids) percent sodium faujasite (Si/Al 1.5) and 70 weight perand 600 cc. water for 2 minutes in a blender. The result- Cent McNamee d was p d i a ner similar s y. after being dried to remove the liquid phase, to that described in Example 19, except that the thermal Was thermally treated at 1200 with 100% Steam for interaction was carried out at 1225 F. with 100 percent 24 hours under a Pressure of The Product steam for hours at atmospheric pressure. 24 6.2 grams lyzed 4.8 Wtperc n Sodium of this product was impregnated under vacuum with 141.5

Table 6 below illustrates that when the as-synthesized f ammonium tungstate l i (0 20 3 gram 1 or alkali metal form of the aluminosilicate is employed, Stem/w 1 m i a 2-step operatign to deposit 10 the matrix Component must be used in an amount come 15 weight percent tungsten. The resulting product, after hesponding t0 at least 50 Percent by Weight based on the ing dried at 230 F., was then impregnated with 141 cc. final composite. of solution containing 56. 75 grams Ni (NO -6H O to TABLE 6 deposit 4 weight percent nickel. The final product was Example 19 20 21 20 then dried for 20 hours at 230 F. and calcined for 10 hours at 1000 F.

l v I ;t r i x hnc., wt. percent 70 50 40 EXample 24 fig gggggggg The particular sample of catalytic composite used in co i g 4 4 4 this test was prepared by mixing 521 grams of sodium o/o 1:511:11;IIIIIIIIIIII 1. 25 li g. dried 22 Weight percent solilds), Co v mercen wit 1 0 grams 0 c amee c ay to constitute a cata ytic tllihififiiafihfifiii i213 2 12 it composite containing 20 weight percent active compoc iie t' igiit 2 g g nent. 3270 cc. of water was used to aid in the dispersion. H2 g f p 3 3 1 The mixing was carried out in a blender by mixing vigor- Dlelte Ad mntage OVer Si/A 5 o- +9 4 +3 4 ously for 2 minutes. Following the mixing, the wet slurry 961cm was dried at 230 F., then pelleted and sized 4-l0 mesh, Example 22 calcined for 10' hours at 1000 =F., and then charged to an automatic cycling unit. In this cyclic unit, the catalyst In this preparation, 47.9 grams of a crystalline aluminowas subjected to alternate cracking and regeneration perisilicate identified as sodium faujasite (Si/A1 1.5; 50.8 ods Theicyclic treatment was as follows:

Sequence Charging Pressure, Temp, F. Stage Time p.s.i.g. (min) 0 950 Regeneration 2O 0 1,1501,200 ..do a0 0 1,200-950 Cooling 15 0-15 950 Pressuring to run conditions. 2 15 950 Steam treat 10 15 950 Cracking l0 15-0 950 Purge and depressur 10 *Steam was 5 weight percent of the oil.

wt. percent solids) was mixed with 600 cc. water and 233 grams of conventional silica-alumina cracking catalyst (10% alumina) which had been pulverized to less than 20 microns. The mixture was blended for 2 minutes. The resulting slurry, after being dried to remove the liquid phase, was thermally treated at 1200 F. with 100% steam for 24 hours under a pressure of 15 p.s.i.g. The product analyzed 1.0 wt. percent sodium. After treating a test sample of the composite with an excess of 25% aqueous ammonium chloride solution at -1-'80 F. for .24 hours, the sample analyzed 0.66 wt. percent sodium. Catalytic evaluation of the catalyst composite for cracking gas oil is shown below in Table 7.

The catalyst was initially evaluated at OAT-C conditions of 4 LHSV, 1.5 C/O and at 900 F. charging wide range Mid-Continent gas oil, and after 70, 145, 217, 290 and 344 cycles as described above. Catalytic results are summarized as follows:

C Gasoline Advantages Over N0. Cycles Vol. Percent Vol. Percent Si/Al at Same Conversion C5+Gasoline Conversion 4.8. 6 27. 1 -S. 9 51. (i 30. 5 7. 3 (i9. 0 50. 4 +3. 2 70. 1 51. 1 +3. 7 74. 3 56. 9 +7. 8 72.0 54. 9 +6. 7 72. 8 50. 2 +7. 7 73. 1 57. 4 +8. 8 73. 8 58. 5 +9. 6 74.1 58. 0 +9. 6 75. 2 60. 0 +10. 6 7+1. 1 59. 0 +10. 6

These data show that, in about 70 cycles of operation, the catalytic composite can be converted to yield catalytically selective composite. Continued cyclic treatment shows continued improvement in catalytic selectivity.

These data show that these catalytic solid-solid interactions can be accomplished at conditions present in commercial units.

As shown above, catalysts of good initial activity can be prepared by steaming blends of matrix material with zeolites of high or low silica content. However, it has been found that such blends of low silica zeolite are unstable unless polyvalent metal compound (oxide or salt) be added to the reaction mixture. Thus, the general 15 method (without added metal compound) produces good, stable catalyst only with aluminosilicates of silicon to aluminum ratio at least as great as 1.5.

The data in Examples 25, 26 and 27, taken with Table 16 (after 72 hours of steaming) gives 20.3 percent conversion. The NaY catalyst, on the other hand, started with an extraordinarily high activity and selectivity, most of which was retained after the steaming process.

8, show that, using kaolinite clay, the NaX product gave catalytic results even poorer than 100' percent kaolinite Example 2 (steam-treated in the same way) by itself. The sodium Zeoiite Y, on the other hand, gave a very active and A 25.9-gram portion of synthetic NaX zeolite (Linde selective catalyst. 13X) (96.8 percent solids) and a 277-gram portion Exam 1e 25 of halloysite clay (81.3 percent solids) were mixed for 2 p minutes with 600 cc. of H 0 in a Waring Blendor. The A batch of kaolinite clay (McNamee) was pelleted resulting slurry was dried overnight at 230 F., pelleted, crushed and screened to give a 500 cc. sample of 4-10 crusiwd and.screeneii to oblauha a 4 1O mfish mesh particles. This material was calcined in air for 10 pamclas; Thls material W skimmed m for 10 hours hours at 1000 F. Half the batch was then treated in i 1000 f, treatmg Wlth 100 Percent for 100 percent steam for 24 hours at 1200 F. and 15 p.s.i.g. hours at 122.5 a atmosphfinc pressufe" It was prior to testing for as Oil crackinm tested for gas oil cracking. The results of this test are 8 given in column 1, Table 9. It was then further treated Example 26 with 100 percent steam for 24 hours at 1200 F. and 15 p.s .1.g. and retested for gas oil cracking. The results of A 261 gram portion of Synthetic NaX Zeolite (Linde this test are given in column 2, Table 9. And, finally, the 13X) (955 percent Solids) and a 258 gram portion of catalyst was further treated with 100 percent steam for kaolinite clay (McNamee) (87.4 percent solids) were an additlonal 48 hoilrs (72 hours 1200. and mixed for 2 minutes with 600 cc. of H 0 in a Waring 15 agam t?sted.for gas 011 crackmg' The Blendor. The resulting slurry was dried overnight at results of thls test are gwen m column Table 230 F., pelleted, ground and screened to obtain 4-10 mesh particles, which were then calcined in air for 10 Exampla 29 hours at 1000 F. The batch was then split in halves. One half was treated in 100 percent steam for 24 hours at A batch of hancyslte clay pellets was Crushed 1200 F. and 15 p.s.i.g. prior to testing for gas oil screened.to Obtain a 250 4 10 mesh cracking cles. This material was calcined in air for 10 hours at 1000 F. It was then treated with 100 percent steam for Example 27 72 hours at 1200 F. and 15 p.s.i.g. prior to testing for gas oil cracking. A 3l-gram portion of synthetic NaY zeolite (80.6 percent solids) and a 259-grarn portion of kaolinite clay E a l 30 (McNamee) (87 percent solids) were mixed for 2 minutes with 600 cc. of H O in a Waring Blendor. The 54.4-gram portion of synthetic NaY Zeolite (46 perresulting slurry was dried overnight at 230 F., pelleted, cent solids) and a 277-gram portion of halloysite (81.3 crushed and screened to obtain 410 mesh particles, which percent solids) were mixed for 2 minutes with 600 cc. of were then calcined in air for 10 hours at 1000 F. The H O in a Waring Blendor. The resulting slurry was dried batch was then split in halves. One half was treated in overnight at 230 F., pelleted, crushed and screened to 100 percent steam for 24 hours at 1200 F. and 15 p.s.i.g. give a batch of 4-10 inesh particles. This material was prior to testing for gas oil cracking. calcined in air for 10 hours at 1000 F. After treating with ,NBLE 8 100 percent steam for 20 hours at 1225 F. and atmospheric pressure, it was tested for gas oil cracking. The Example 25 2s 27 results of this test are given in column 5, Table 9. It was Sieve 10% NaX then further treated with 100 percent steam for 24 hours Kaolinite, percent 100 0 90 at 1200 F. and 15 p.s.i.g. and retested for gas oil crack- 38? CrackmgData ing. The results of this test are given in column 6, Table 9. Conversion. vol. percent 22.8 10.3 59.3 And, finally, the catalyst was further treated with steam gggfsjf j ig g g ggg ff 3::" ?:2 for an additional 48 hours (72 hours total) at 1200 F. y as. p nt. ti and 15 p.s.i.g. and again tested for gas oil cracking. The Coke percent 8 2 2 results of this test are given in column 7, Table 9.

TABLE 9 Column No.

Example 28 29 30 Sieve, 10% NaX NaY llalloysite, percent 90 100 00 Hours at 15 p.s.i.g., Steam 0 24 72 72 0 24 72 Gas Oil Cracking Data (CATC) at 4 LIISV and 1.5 0/0:

Conversion, vol. percent 44. 0 33. 5 29. 5 20. 3 75.2 70. 6 60. 3 (35+ Gasoline, vol. percent 39.1 32. 6 27. 1 18. 1 61.3 58. 6 51. 5 Total 04's, vol. percent-.. 8. 2 5.2 4.9 3. 4 17. 7 15. 6 13.2 Dry Gas, wt. pcrcent, 3.8 2. 9 2. 5 2.2 7.3 6.3 5.1 Coke, wt. percent 1.0 U. 9 0. 7 0. 6 2. 2 1. 8 1. 1

The data in Examples 28, 29 and 30, taken with Table We claim:

9, show that it is possible to prepare a catalyst from NaX and halloysite having a moderate activity (though less than the activity of conventional silica-alumina) and good selectivity. However, the stability of the catalyst is very poor. After 72 hours of pressure steaming, it gives a conversion of only 29.5 percent, and halloysite clay by itself 1. A process for preparing a catalyst composite which comprises forming a reaction mixture comprising:

.(a) a matrix composed of at least two inorganic oxides, wherein at least one inorganic oxide is selected from the group consisting of siliceous oxides and alumina-containing oxides, with the proviso that 17 the siliceous oxide be present in amounts no greater than 90 weight percent, based on the weight of the matrix, and any alumina-containing oxide be present in amounts of at least 10 weight percent, based on the weight of the matrix; and

(b) a steam-unstable, base exchangeable crystalline metal aluminosilicate having a silicon to aluminum ratio of at least about 1.5 and characterized by pore openings greater than 6 and less than 15 Angstrom units in diameter, and containing greater than 4 weight percent alkali metal, said aluminosilicate being present in an amount less than 60 percent by weight, based on the final composite; and thereafter heating said reaction mixture in the presence of steam at temperatures of at least 800 F. for at least one-half hour in order to reduce the exchangeable alkali metal content of the reaction mixture and to provide a steam stable catalyst composition having an exchangeable alkali metal content of not more than 0.6 weight percent as determined by base exchange with an excess of 25 percent aqueous ammonium chloride solution at 180 F. for 24 hours.

2. The process of claim 1 wherein at least one of the inorganic oxides of the matrix is alumina present in an amount ranging from 15 to 55 weight percent based on total matrix.

3. The process of claim 2 wherein the matrix is a 18 member selected from the group consisting of natural clay, chemically treated clay and calcined clay.

4. The process of claim 2 wherein the matrix is a synthetic composite of silica and alumina having an alumina content of at least 25 weight percent.

5. The process of claim 2 wherein the aluminosilicate is an alkali metal aluminosilicate which is present in an amount less than 25 weight percent based on the final composite.

6. The process of claim 2 wherein the aluminosilicate has the crystallographic structure of faujasite.

7. The process of claim 3 wherein the aluminosilicate has the crystallographic structure of faujasite.

8. The process of claim 3 wherein the matrix is a clay of the kaolinite group.

9. The process of claim 8 wherein the aluminosilicate has the crystallographic structure of faujasite.

10. The process of claim 8 wherein the catalyst com position has an exchangeable alkali metal content of not more than 0.4 weight percent.

References Cited UNITED STATES PATENTS ABRAHAM RIMENS, Primary Examiner. 

